Theoretical energy requirement

The theoretical energy requirement for an electrochemical process is given by... 

The theoretical energy requirement for the burning of Portiand cement clinker can be calculated from the heat requirements and energy recovery from the various stages of the process. Knowledge of the specific heats of the various phases, and the heats of decomposition, transformation, and reaction then permits calculation of the net theoretical energy requirement of 1760 kj (420 kcal) for 1 kg of clinker from 1.55 kg of dry CaCO and kaolin (see Clays) (8). 

The Hall-Heroult process is a prodigious consumer of electrical energy. The energy required to produce 1 ton of aluminum from ore is more than twice that required to produce 1 ton of copper and ten times that for 1 ton of steel. More than 75% of this energy is consumed in the reduction of alumina to aluminum metal. The reasons for this high energy consumption have been presented in Table 6.18. The theoretical energy requirement for... 

Once the minimum theoretical energy requirements and applicable process options have been determined, a formal facilitated workshop follows to modify the process or facility to bring the design closer to the thermodynamic optimum within project economic constraints. 

Among the more important economic factors involved in large-scale conversion of saline water are the amount and cost of the energy necessary for operation of the conversion processes. The purpose of this paper is to establish the theoretical energy required by certain idealized conversion processes utilizing freezing. 

The theoretical energy requirement for the electrochemical reaction in aluminum electrolysis is 6.34 kWh/kg Al (at a current efficiency of 100%). The rest of the energy output is in the form of heat loss from the cell body it varies largely from 5.5 to 9.0 kWh/kg Al depending on the type of cell. 

Theoretical energy required to heat ambient air to burner outlet temperature. 

The theoretical energy requirement to achieve the above process can be calculated as follows. First, the magnesite rock has to be raised from ambient temperature to the temperature of decomposition. Second, once at the temperature of decomposition, there is another energy component, the enthalpy of decomposition, required to decompose the magnesite to magnesium oxide and carbon dioxide. 

Thermodynamics and Energy Requirements. Dodge and E shay a (13) pointed out that the theoretical energy requirement is not a unique quantity but depends on certain variables and assumptions. There is an absolute minimum... 

The theoretical energy required for the process is that for establishing the desired concentration of H+ and OH -ions in the outer phases of the membrane from their concentration in the membrane which is approximately 10 mol/L. The free energy of this process is ... 

As can be seen from the reaction equations, the splitting of water requires different amounts of energy dependent on how much of the carbon contained in the (fossil) raw materials is converted into CO2. The energy released during this conversion is consumed in the splitting process and does not need to be introduced from outside. The theoretical energies required for the production of 1 Nm of hydrogen are listed in Table 5-4. 

The theoretical energy requirement for chlorine and caustic production was shown in Section 4.4.2 to be ... 

The pumping efficiency is the ratio of the theoretical energy requirement to develop pressure AP (= VAP) divided by the actual energy requirement (= dZ,ii). Thus, the pumping efficiency in the channel can be written as ... 

A methanol plant is very energy intensive. The theoretical energy required to convert pure methane to methanol and hydrogen, Equation (27), is 5.97 Gcal (LHV)/t, and the theoretical energy required to produce methanol from ethane. Equation (30), is 5.32 Gcal (LHV)/t ... 

As the carbon content of the feedstock increases, the theoretical energy required to produce methanol decreases. This is why heavier feedstocks are often used for methanol production. 

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